Rum Procedure Advice

[gundog48]

I was wondering if you'd take a look at my rum procedure and tell me what you think, I'm trying to produce something with some decent esters, but I'm looking for a fairly straightforward procedure. I've had problems in the past with stuck fermentations and pH crashing, which I'm hoping to deal with.

The wash:

Distillmax RM
1Kg Sugar for every 5Kg Molasses (should be equivilent to high test molasses)
0.05g/L DAP
0.015g/L Epsom Salts
Start at 10°B, then adding 2 more additions every 10 hours to target 10% ABV
Ferment at 32°C

Handling Dunder
Dunder will be added in lieu of water at a rate of 20% on the second fermentation (I don't have any for the first!) And 10% on subsequent batches.

The dunder will be removed from the still and I will add calcium hydroxide to achive a pH of 4-4.5, I am relying on this to buffer my fermentations.

It will typically go in fresh, but may be stored between 'campaigns'

Stripping Run

Charge the wash. If the pH is above around 3.5, adjust down with 80% lactic acid. I'm worried that the CaOH in the dunder will keep all my acids locked up as salts, so I want to make sure they are properly liberated. Maybe I'll use sulphuric?

I will run the distillation hard towards the end to collect as much of the volatile acids and any esters as possible.

Spirit Run

Add a small amount of sulphuric acid to the low wines to encourage esterification. Unsure exactly how much, shouldn't need much, probably aim for a pH of 3-4. May get my chemist friend to do a titration on the low wines! Will run under full reflux for 30 mins to an hour, then collect under a small amount of reflux, hopefully getting a heart cut around 80%ABV.

Would love to know your thoughts, specifically around nutrition and buffering. I've not heard of people specifically using ph-adjusted dunder to buffer their fermentations. I really don't like adjusting fermentation pH on the fly, so this sounds like a good way forward for me.